1. Technical Field
The present invention relates to a travel control apparatus for a vehicle, which performs automatic driving control by recognizing a travel environment and detecting travel information relating to a vehicle equipped with the apparatus.
2. Related Art
Recently, various apparatuses employing automatic driving techniques that enable a driver to drive a vehicle in increased comfort and more safely have been developed and proposed. Japanese Unexamined Patent Application Publication No. 2003-63373, for example, discloses a technique employed in an automatic evacuation apparatus for a vehicle to stop the vehicle in a predetermined evacuation region when a fault occurs in a steering system, by controlling a brake force applied to left and right vehicle wheels in order to modify a path of the vehicle.
A case in which an environment recognition function fails or stops during automatic driving and a driver does not immediately perform a backup operation may be envisaged as one situation in which automatic evacuation such as that disclosed in Japanese Unexamined Patent Application Publication No. 2003-63373 is required. Under these conditions, the reliability of information relating to a most recently recognized environment decreases gradually over time, and with less reliable environment information it is difficult to complete an automatic evacuation operation such that the vehicle is parked on a road shoulder even using the automatic evacuation apparatus disclosed in Japanese Unexamined Patent Application Publication No. 2003-63373. As a result, the evacuation operation cannot be performed sufficiently safely.